Catalysts



Patented Feb 28, 1939 UNITED STATES CATALYSTS Boris Malishev, Elizabeth,N. J.

No Drawing. Application March 9, 1938, Serial No. 194,769

'1 Claims.

My invention relates to catalytic agents and methods of theirpreparation and has particular reference to catalytic agents forrefining, synthesising and polymerizing hydrocarbons.

This is a continuation in part 'of my application No. 140,441, filed May3, 1937 with reference also to my copending application Serial No.205,724, filed May 3, 1938.

In my foregoing application I described a method of preparation of acatalyst from sulfuric acid anhydride, or sludge acid, with a phosphatecompound such as phosphate rock (phosphorite) and also other mineralphosphates such as apatite, vivianite, wavelite, and monazite and theirsynthetic equivalents by calcining the mixture at a temperature above245 C. and preferably above 300 but below the red heat. It may be notedthat none ofthe foregoing minerals represents a compound of a singlephosphate, but a phosphate carbonate and silicate, of several elements.

I have also obtained a catalyst of equal. agtivity by using othersynthetic and natural phosphates instead of the above phosphatecompounds, such as bone-ash, phosphatic slag, Thomas slag, (fordefinition see Chemical Dictionary by Ingo W. D. Hackh, 1929, p. 731),superphosphates, etc.

It is known that acid sulfates can be converted by heating intopyrosulfates, which on further heating readily decompose into sulfuricacid an- .hydride, the latter being the active agent in the process ofpreparation of my catalyst. All the sulfur containing compounds used inmy process such as sulfuric acid anhydride, sulfuric acid, alkali acidsulfates, pyrosulfates' and sludge acid, have one general characteristicin that they all give acid reaction due to sulfuric acid in theiraqueous solutions. fore, compounds with an acid sulfuric acid reactionin water. The cause of the catalytic activity, I believe, is due to theinformation of phosphoric anhydride during calcination with sulfuricanhydride, as follows:

Perhaps part of P205 is converted into a nonvolatile isomericmodification and forms a'dcuble anhydride with SiOz and S03. As isknown, acid sulfates when heated to a temperature as required forcalcination in my process, 1. e. below red heat, decompose into water,sulfuric acid and pyrosul fates. Such a decomposition takes place at atemperature between 316 and 400- C. for sodium acid sulfate.Pyrosulfates decompose They may be called, therecerium, thorium, etc.

near their melting point into sulfuric anhydride. and neutral sulfates.This temperature for sodium pyrosulfatcs is about 400 to 500 C. Thesetemperatures lie below red heat which by definition is between 585 and840 C. The decomposi- 5 tion is complete when all acid fumes areexpelled. As I disclosed in the foregoing application, sludge acid canbe used for the preparation of my catalyst, the product being butslightly less active than the catalyst prepared with sulfuric acidanhydride. Certain precautions must, be taken in the process, however,in order to completely destroy or eliminate'tarry organic substances andcarbon formed which may' interfere with the proper contact of 'thecatalyst with the substance to be treated. For this purpose the processis conducted as follows: at first, an intimatemixture of inorganicphosphate, siliceous material and sludge acid is calcined at thetemperature of about 300 C. In the reaction taking 20 place during thiscalcination the catalyst is produced. At the same time volatileconstituents of the organic matter are expelled. In order to remove theresidual organic matter which is very firmly bound to the catalyst, themass is first 25 disintegrated with steam at 300 C. and is then calcinedin the atmosphere of airor oxygen at a temperature above 300 C. butbelow red heat until all the organic matter and carbon are burned out.The resultant mass which is deadburned and not very active, is activatedwith steam. The steam treatment is also beneficial for producing a massof good pelleting or briquetting qualities.

Occasionally, when sludge acid is used, the above calcination withoxygen does not remove all of the organic matter and carbon, in whichcase the catalyst 'does not acquire its full activity. I have found,however, that the complete oxydation of the organic matter and carboncan be effected by adding suitable oxidizing agents to the mixtureduring the process of calcination, the resulting product then possessingfull catalytic activity. Satisfactory oxidation is obtained with cheapminerals such as Chilean saltpeter of pyrolusite (M1102), also withother oxidizing agents or catalytic oxygen carriers in presence ofoxygen. Thus, for instance, I have obtained good results with oxides andacids of nitrogen, metal oxides and peroxides, peracids' and their saltssuch as perborates, persulfates, etc. "'As oxygen carriers I used saltsof manganese; chromium, I have also' found that the presence of amineral acid is required in order to obtainthe full effect of theoxidizing agent, and for this purpose sulfuric acid can be used as thecheapest.

Example I.--3000 gm. of phosphate rock is .mixed with 3000 gm. ofdiatomaceous earth and to this mixture is added 6000 gm. of acid sludgeobtained from treating gasoline, forming a paste. The latter is calcinedfor 3 hrs. at 300 C., then roasted with air or oxygen to burn out themost of the organic matter and carbon. The product is powdered and mixedwith 300 gm. of powdered pyrolusite and 300 gm. of sulfuric acid forminga paste. The mixture is calcined for 20 minutes and then treated withsteam for 2 hrs. at 300 C. The product is powdered and briquetted intopellets of about in. in diameter.

Example II.-Unrefined cracked gasoline is pumped through my catalyst ata temperature between 200 and 300 C. and at a pressure sufflcient tomaintain the liquid state. Gases containing olefines, such as areobtained in cracking petroleum oil, are admitted to the hot gasoline ina quantity sufhcient to form a mixture of gas and liquid. The productobtained is redistilled to the desired end-point, the yield of gasolinebeing greater than obtained in the process without the cracked gases.The oleflnes are apparently polymerized and condensed with aromaticcompounds.

The application of my catalyst does not necessarily require theforegoing temperatures. I-have found that when my catalyst is used attemperatures between about 400 C. and 600 C. and at the atmosphericpressure, although some considerable cracking of hydrocarbons takesplace, yet the polymerization and condensation reactions still prevail,however, less stable hydrocarbons being cracks-.1 and the fragments thusformed 'simultaneously polymerized and condensed into a more stableproduct. For example, I converted normally gaseous hydrocarbons of themethane series and a mixture of these hydrocarbons with olefines into aliquid motor fuel. Such condensation took place also with aromatichydrocarbons in the mixture.

The process can be also conducted in two steps; at first, cracking theraw material at ordinary pressure,as described above, and thenpolymerizing and condensing the cracked products at an elevated pressuresuch as 100 to 1000,1bs. per sq. inch, and at somewhat lowertemperature, from 150 to 300 C. In this manner more gaseous products areconverted into liquid fuel.

In my experiments, I have been using diatomaceous earth, such askieselguhr. I have also found that other siliceous adsorbing materialsor minerals can be used, such asfinely ground quartz.

Example III.- -3000 gm. of finely powdered phosphate rock containingabout 70% of 09.:(104): is mixed with 3000 gm. of powdered diatomaceousearth and to this mixture is added 3000 gm. of 20% fuming sulfuric acid,forming a paste. The latter is calcined until the acid fumes areexpelled. The product may be powdered and briquetted into pellets ofabout in. in diameter.

Example IV.The pellets obtained in the fore-- going example are chargedinto a vertical cylindrical reaction chamber 3 in. diameter inside and 5feet high, electrically heated. Cracked unrefined gasoline is pumpedinto, the bottom of the reaction chamber and is maintained at thepressure of 250 lbs. per square-inch and at a temperature from 250 to300 C. The treated gasoline is then removed at the top of the chamberand redistilled to the desirable end point, representing completelyrefined product.

Ewample IL-Benzene is pumped through this catalytic mass and ethylene isforced through it at the pressure of 450 lbs. per square inch incountercurrent to benzene at the temperature of 250 C. The issuingliquid is fractionated to separate ethyl benzene from unreacted benzene.Ethylization is 60% complete.

Example VI.Ethylene at initial pressure of 700 lbs. per square inch isheated in an autoclave for 8 hours at 340 C. with my catalyst.

About 20% of ethylene is polymerized to a gasosisting of a mineralphosphate, phosphatic slag,

Thomas'slag, and superphosphate, with a substance taken from the groupconsisting of sulfuric acid and sludge acid, with an adsorbent silicioussubstance, the mixture being calcined at a temperature sufficient tocause the substance of the first group to be decomposed by the substanceof the second group and the free sulfuric acid to be largely expelled,but below red heat.

3. A catalyst comprising the product of a mixture of a substance takenfrom the group consisting of a. mineral phosphate, phosphatic slag,Thomas slag, and superphosphate, in presence of a substancecharacterized by its ability to hydrolyze in water to yield sulfuricacid and with an adsorbent silicious substance, the mixture beingcalcined at a temperature sufficient to decompose the substance of thefirst group by the substance of the second group, and to largely expelthe free sulfuric acid, but below red heat.

4. A step in the process of preparation of a catalyst, consisting inmixing together a substance taken from the group consisting of a mineralphosphate, phosphatic slag, Thomas slag, and superphosphate, with asubstance characterized by its ability to hydrolyze in water to yieldsulfuric acid, and with an adsorbent silicious substance, and calciningthe mixture at a temperature sufli'eient to decompose the firstsubstance by the second substance, and to largely expel acid fumes ofthe substance having acidic sulfuric acid reaction but below red heat,the quantity of the second substance being sufficient for decomposi tionof the first substance.

5. A step in the process of preparation of a catalyst, consisting inmixing together a substance taken from the group consisting of a mineralphosphate, phosphatic slag, Thomas slag,

. and superphosphate, with a substance taken from the group consistingof sulfuric acid, sulfuric acid anhydride, and sludge acid, and with anadso'rbphatic slag, and superphosphate, with an adsorbent silicioussubstance in presence of a substance characterized by its ability tohydmlize in water to yield sulfuric acid, the calcination beingconducted at a temperature suiilcient for substantially expelling theacid fumes of the substance having acidic sulfuric acid reaction butbelow red heat, the quantity of the latter substance being sufllcientfor decomposing the phosphatic substance.

7. A method of preparation of a catalyst, comprising the steps ofpreparing an intimate powdered mixture of a substance taken from thegroup consisting of phosphate rock. apatite, vivianite, monazite, Thomas8188. plmsphatic slag, and superphosphate, with an adsorbent silicioussubstance, and with sludge acid disintegrating the mixture'with steam,calcining the mixture in presence of an oxidizing agent at a temperaturesufllcient for substantially expelling sludge acid fumes but below redheat, the quantity of the latter substance being sufilcient fordecomproduct with steam.

- BORIS MALISHEV.

-a,ue,cs4 U '13 posing the phosphatic substance and treating the 10 I

